It's the same thing for all pay ranges for the various subgrades. The ranges are wide but the annual increments are small. So while you may think - wow, GEO4 can earn 7.8k gross?!?! But that is the CEILING. The vast majority of GEO4s get promoted into the grade to draw around 5.6k to 6k, give and take a bit. At approx +175 per annual increment on average, the bulk of GEO4s in service at any given time are hardly anywhere near the ceiling.

The same principle applies for pretty much any other timescale subgrade, except GEO5.